Starter for internal combustion engine



March 7, 1961 F. 0. DE MXLLAR STARTER FOR INTERNAL COMBUSTION ENGINE 2Sheets-Sheet 1 o a 2 a Z 4 2 W amw l a I I l r i u w [2 w. a 1 M 8 M a m9 l I 2 0 lk L a v4 0 d e 1 i F March 7, 1961 F. 0. DE MILLAR 2,973,754

, STARTER FOR INTERNAL COMBUSTION ENGINE Filed 001;. 27, 1958 2Sheets-Sheet 2 Fio yd 0.12am 21y flaw, ammo/ M fliffaameys Uni edst t sP ten '0 STARTER non INTERNAL COMBUSTION ENGINE Floyd 0. De Millar,Framingham, Mass., assignor to Radian Corporation, Framingharn Center,Mass., a corporation of Massachusetts 7 Filed Oct. 27', 1958, Ser. No.769,843

4 Claims. (Cl. 123-179) itself with a motor shaft and becomes wound whena v handle member is turned, and which disengages itself afterfrictional resistance and the resistance ofthe motor compression areexceeded and the spring becomes unwound.

Still another object is to provide a starter mechanism characterized bya high degree of safety in use which will avoid accidental reversing ofthe handle or other undesirable interference with the operation.

The nature of the invention and its objects will be more fullyunderstood and appreciated from the following description of a preferredembodiment selected for purposes of illustration and shown in theaccompanying drawings, in which- Fig. 1 is a fragmentary plan viewshowing the starter mechanism of the invention mounted upon a motor ofthe class described above;

Fig. 2 is a cross-section taken on the line 2--2 of Fig. 1; i a

Fig. 3 is a cross-section taken'on the line 3-3 of Fig. 2' and i Fig. 4is a cross-section taken on the line 44 of Fig.2.

In the structure shown in the accompanying drawings, numeral 2 denotes amotor which drives a shaft 4. In one specific aspect, the invention isconcerned with a motor type wherein the shaft is driven about a verticalaxis and presents an upper end which can be engaged by mechanism forcranking the motor. The invention is further concerned with a motorwhich is characterized by a relatively high compression. In such amotor, in addition to ordinary frictional resistance, the relativelyhigh compression tends to impart to the shaft 4 a very considerableresistance to turning forces exerted externally of this shaft.

In accordance with the invention, I have devised, for the class ofmotorindicated, a special spring starter mechanism which is designed toutilize the resistance of the shaft 4 to wind up a coiled spring to apredetermined point. When the frictional resistance and compressionresistance of the motor and shaft are exceeded by the energy stored inthe coiled spring, a rapid turning of the shaft and motor is realizedfor starting purposes.

Referring more in detail to the drawings, my improved starter mechanismincludes a stationary housing 6 which is adapted to be secured to thetop of the motor 2 by fastenings such as the screws 6a which extendthrough a flanged portion 6b. Mounted for rotation ina bearing portion 8of the housing 6, isa crank shaft 10 which has secured to its upper enda handle 12. The handle 12 is adapted to be turned in a clockwisedirection, as viewed in Fig. 1 and is held at one point, to preventcounterclockwise rotation, by means of a ratchet and pawl unit.

This mechanism includes a ratchet wheel 14 and a pawl 16. The pawl 16 ispivotally mounted within the housing 6 as best shown in Fig. 2 on apivot element 18, and a spring 20 maintains the pawl in a spring loadedstate. The ratchet wheel 14 is secured by rivets 22 to a spring casing24 which is solidly secured in some convenient manner to the crank shaft10. Preferably thespring casing may be formed with a shouldered hubportion 24a around which the ratchet is snugly fitted as shown in Fig.2,,although other arrangements for accomplishing this purpose may beemployed.

Located in coiled relationship within the spring casing 24 is a spring26, the outer convolution of which terminates in a curved extremity 26a(Fig. 3) adapted to be interlocked with a slot 24b in the casing 24. Theinner end of the spring 26 is provided with a hook element 28 which ishinged on a spring pivot 30 normally adapted to swing the hook elementoutwardly when the spring is in an uncoiled position. The book element28 is designed to provide for connecting the inner end of the coiledspring 26 to the motor shaft 4 so that the springmay be tightened whileheld by the initial frictional resistance and the compression of themotor.

An important feature of the invention is a novel means for engaging thehook element 28 with the motor shaft 4. This novel means includes amagnet piece 32 which is received in some suitable manner as by means ofa recessed bushing 34 keyed to the shaft as shown in Fig. 3. Thefunction of the magnet is to attract and hold the hook element 28 when awinding movement is effected in the coiled spring through the handle 12.A recessed edge of the hook element 28 tends to be drawn around thebushing 34 and becomes anchored in a notch in the bushing closelyadjacent to the magnet in the position shown in Fig. 3.

The initial frictional resistance and the compression resistance of themotor hold the shaft 4 in a relatively fixed position for a short periodwhile the spring and casing are wound in a clockwise direction as viewedin Fig. 3. At a point at which initial frictional resistance and theresistance of the motor compression are exceeded by the energy thusstored in the coiled spring, the shaft 4 is turned and rapidly spunWhile the spring is releasing its stored energy. When the spring hasbecome completely unwound the continued revolution of the notchedbushing 34 and the pressure of the spring pivot 30 cause the hookelement 28 to move outwardly away from engagement with the magnet andnotch described.

From the foregoing description it will be observed that I have disclosedan improved spring mechanism for turning a motor shaft of the verticalaxis type and the entire winding operation is adequately protected atall times by means of the ratchet and pawl unit, so that actual releaseof the handle 12 cannot occur. The entire assembly is of a simplifiedconstruction resulting from taking advantage of the compressionresistance of certain types of motors. Although the starter mechanismand its operation has been described with respect to a shaft which isturned about a vertical axis, it should be nevertheless understood thatgravity forces are not necessary and the operation of the device mayalso be successfully carried out with respect to shafts which turn aboutaxes other than vertical axes.

While I have shown and described a preferred embodiment of theinvention, it is intended the invention may Patented Mar. 7,. 1961 bemodified in various respects as defined by the appended claims.

Having thus described my invention, what I claim is:

1. In combination a crank shaft, a motor connected in drivingrelationship with one end of the crank shaft, said motor having arelatively high compression capable of imparting to the crank shaft anappreciable resistance to turning forces exerted on the opposite end ofsaid crank shaft, a starter mechanism mounted on the motor, saidmechanism including a housing, a starter shaft and handle unitrotatively mounted in the housing, a spring casing secured to thestarter shaft and rotatable with it, spring engaging means fixed to thecrank shaft, a coiled spring having its outer end anchored to the springcasing, means at the inner end of the spring for interlocking saidspring with the spring engaging means on said crank shaft, said springconstructed and arranged to wind upon itself when said starter shaft andhandle unit are turned, and means for so winding said spring upon itselfonly in response to resistance in said crank shaft from inertia, initialresistance, and cylinder compression; whereby con tinued turning of saidstarter shaft and handle unit turns said crank shaft past the point ofcylinder compression of said motor and overcomes said initial resistanceand inertia; and whereby said spring thereafter releases its said storedenergy for urging said crank shaft into higher velocity rotation forstarting said motor.

2. A structure according to claim 1 in which the spring engaging meansincludes a magnet for releasably holding a hook element.

3. A structure according to claim 1 in which said starter shaft andhandle unit is prevented from turning in one direction by means of arachet and a spring loaded pawl, said pawl being mounted for engagingsaid rachet.

4. A structure according to claim 1 in which the spring engaging meansincludes a magnet for releasably holding the hook element, and in whichthe starter shaft and handle unit is prevented from turning in onedirection by means of a rachet and a spring loaded pawl, said pawlmounted for engaging said rachet.

References Cited in the file of this patent UNITED STATES PATENTS I l q

